NEW YORK (CNN/Money) - Wal-Mart Stores Inc. has broadened its corporate policy prohibiting discrimination to cover gay and lesbian workers, the company confirmed with CNN Wednesday.

Tom Williams, a Wal-Mart spokesman told CNN that the company implemented the changes "because it was the right thing to do for our 1.5 million employees. We feel that they need to be treated with respect and feel valued--no exceptions."

Pride Foundation, a Seattle gay rights group, disclosed that it received a letter last week from Wal-Mart outlining the new anti-discrimination policies, the New York Times reported.

A spokeswoman told the newspaper that Wal-Mart sent out letters Tuesday to its 3,500 stores, after which store managers would explain the change to more than 1 million employees.

Along with prodding from groups, such as the Pride Foundation, the spokeswoman said several gay employees wrote senior management about six weeks ago to say they would "continue to feel excluded" unless Wal-Mart changed its policies, according to the newspaper.

Gay rights groups have made significant headway in recent weeks, particularly as a result of the U.S. Supreme Court's decision to strike down a Texas sodomy law.

Wal-Mart has raised eyebrows and attracted praise from various groups in recent months. The retailer decided to stop selling certain men's magazines it believed were too explicit, and it does not sell compact discs with labels that warn of explicit lyrics.

Wal-Mart rolled out check-out aisle magazine racks last month that block out views of racy magazine headlines it feels are too provocative.

Shares of Wal-Mart (WMT: Research, Estimates) rose 68 cents Tuesday to close at $54.35.